Added the ability to specify the rules for an optional WAF to attach to the app

dev/dev.ts

@@ -24,6 +24,8 @@ const descriptionWithTag = (tag?: string) =>
 // to point to other PR branches etc
 const DEV_DEPLOYED_IMAGE_TAG = "0.4.4";
 
+let rulePriorityCounter = 0;
+
 /**
  * Stack for dev
  */
@@ -64,5 +66,91 @@ new ElsaDataStack(
       enableAccessPoints: true,
     },
     databaseName: "elsa_data",
+    wafRules: [
+      {
+        name: "LimitRequests100",
+        priority: rulePriorityCounter++,
+        action: {
+          block: {},
+        },
+        statement: {
+          rateBasedStatement: {
+            // given our site is not one where you'd expect high traffic - we set this to
+            // the minimum, and we will see how that plays out
+            limit: 100,
+            aggregateKeyType: "IP",
+          },
+        },
+        visibilityConfig: {
+          sampledRequestsEnabled: true,
+          cloudWatchMetricsEnabled: true,
+          metricName: "LimitRequests100",
+        },
+      },
+      {
+        name: "AllowedCountriesOnly",
+        priority: rulePriorityCounter++,
+        action: {
+          block: {},
+        },
+        statement: {
+          notStatement: {
+            statement: {
+              geoMatchStatement: {
+                // block traffic if not from below
+                countryCodes: ["AU"],
+              },
+            },
+          },
+        },
+        visibilityConfig: {
+          sampledRequestsEnabled: true,
+          cloudWatchMetricsEnabled: true,
+          metricName: "AllowedCountriesOnly",
+        },
+      },
+      {
+        name: "AWS-AWSManagedRulesCommonRuleSet",
+        priority: rulePriorityCounter++,
+        statement: {
+          managedRuleGroupStatement: {
+            name: "AWSManagedRulesCommonRuleSet",
+            vendorName: "AWS",
+            // an example of how we might want to exclude rules
+            // excludedRules: [
+            //  {
+            //    name: "SizeRestrictions_BODY",
+            //  },
+            //],
+          },
+        },
+        overrideAction: {
+          none: {},
+        },
+        visibilityConfig: {
+          sampledRequestsEnabled: true,
+          cloudWatchMetricsEnabled: true,
+          metricName: "AWS-AWSManagedRulesCommonRuleSet",
+        },
+      },
+      {
+        name: "AWS-AWSManagedRulesAmazonIpReputationList",
+        priority: rulePriorityCounter++,
+        statement: {
+          managedRuleGroupStatement: {
+            vendorName: "AWS",
+            name: "AWSManagedRulesAmazonIpReputationList",
+          },
+        },
+        overrideAction: {
+          none: {},
+        },
+        visibilityConfig: {
+          sampledRequestsEnabled: true,
+          cloudWatchMetricsEnabled: true,
+          metricName: "AWS-AWSManagedRulesAmazonIpReputationList",
+        },
+      },
+    ],
   }
 );

packages/aws-application/app/elsa-data-application-app-runner-construct.ts

@@ -19,6 +19,7 @@ import { IBucket } from "aws-cdk-lib/aws-s3";
 import { ContainerConstruct } from "../construct/container-construct";
 import { IHostedZone } from "aws-cdk-lib/aws-route53";
 import { ICertificate } from "aws-cdk-lib/aws-certificatemanager";
+import { CfnWebACL, CfnWebACLAssociation } from "aws-cdk-lib/aws-wafv2";
 
 interface Props extends ElsaDataApplicationSettings {
   readonly vpc: ec2.IVpc;
@@ -109,6 +110,26 @@ export class ElsaDataApplicationAppRunnerConstruct extends Construct {
       vpcConnector: vpcConnector,
     });
 
+    if (props.wafRules && props.wafRules.length > 0) {
+      const cfnWebAcl = new CfnWebACL(this, "WebAcl", {
+        defaultAction: {
+          allow: {},
+        },
+        scope: "REGIONAL",
+        visibilityConfig: {
+          cloudWatchMetricsEnabled: true,
+          metricName: "MetricForWebACLCDK",
+          sampledRequestsEnabled: true,
+        },
+        rules: props.wafRules,
+      });
+
+      new CfnWebACLAssociation(this, "WebAclAssociation", {
+        resourceArn: appService.serviceArn,
+        webAclArn: cfnWebAcl.attrArn,
+      });
+    }
+
     // register a cloudMapService for the Application in our namespace
     // chose a sensible default - but allow an alteration in case I guess someone might
     // want to run two Elsa *in the same infrastructure*

packages/aws-application/elsa-data-application-settings.ts

@@ -1,3 +1,5 @@
+import { CfnWebACL } from "aws-cdk-lib/aws-wafv2";
+
 /**
  * The user settable settings for the Elsa Data application service.
  */
@@ -83,6 +85,12 @@ export interface ElsaDataApplicationSettings {
    * The cpu assigned to the Elsa Data application container - defaults to something sensible
    */
   readonly cpu?: number;
+
+  /**
+   * If present and non-empty - tells us to use these rules for establishing a WAF.
+   * If not present, then no WAF is installed.
+   */
+  readonly wafRules?: CfnWebACL.RuleProperty[];
 }
 
 export interface ElsaDataApplicationBuildLocal {